This application responds to NIMH PA-10-038, Dissemination and Implementation Research in Health with a proposed study examining the major public health priority of how to achieve sustained use of evidence- based psychotherapies. It builds on the existing infrastructure and preliminary findings from a RC1 MH088454 that investigated the initial adoption of two evidence-based treatments (Prolonged Exposure - PE and Cognitive Processing Therapy - CPT) for Posttraumatic Stress Disorder (PTSD) in an unprecedented roll out occurring in the Department of Veterans Affairs (VA) residential treatment settings. An understanding of factors influencing sustained use of evidence-based practices among VA PTSD treatment providers are urgently needed due to an influx of over a million soldiers returning from wars in Iraq and Afghanistan and a recent unexpected flood of Vietnam Veterans entering treatment. When inadequately treated, PTSD can become a chronic disorder contributing to substantial psychological and physical impairments, as well as social and occupational disabilities. Utilizing a theory-driven, empirically-based, multi-level framework, this application proposes to follow for several years clinicians from the VA residential PTSD treatment settings who were studied in the RC1 to determine the extent to which their use of PE and CPT have been sustained and in what form. The investigation assesses organizational and clinician factors expected to influence sustained use, with particular emphasis placed on clinicians' perceptions of the therapies, organizational support, social networks and peer opinion leaders. Another innovative feature of the proposed research is an examination of the extent to which sustained use of these two evidence-based treatments translates into improved patient outcomes, veterans' PTSD symptoms, substance abuse, violent behavior, and employment will also be examined. The proposed study will be conducted in partnership with the Northeast Program Evaluation Program (NEPEC), which monitors all VA mental health programming nationwide, and the National Center for PTSD, which oversees the dissemination of PE and CPT nationally in VA. Quantitative and qualitative assessments of psychotherapy providers in residential PTSD treatment settings will include online self-administered questionnaires, semi-structured interviews and structured reflective journaling. Measures of PE and CPT fidelity include clinician self-report, clinician encounter progress notes from de-identified national database, and interaction with standardized patients. Implementation outcomes will be conceptualized in terms full, partial, and modified sustained use by programs and individual providers, as well as patient psychiatric outcomes.